Single-Click to Open
I always use Nautilus and Dolphin with Single-Click open because it's faster than clicking twice.
Nautilus' implementation leaves a little to be desired because it doesn't introduce handles in the top right you can click to select the file/folder when in Single-Click mode, so you need to CTRL+CLICK to select files/folders. Dolphin's behaviour is better here. But both implementations work fine.
This can be a good enhancement for Cosmic Files
Considering cosmic isn't planning on being familiar like windows in any way shape or form, shouldn't single click to open be the default? It's better in every way except familiarity as far as I'm aware.
IMHO single-clicking to open a file is an absolutely necessary feature and is expected behavior. It's the very first thing I enable when installing PopOS 22.04.